Automatic switching mechanism.



F. A. LUNDQUIST.

AUTOMATIC SWITCHING MECHANISM.

APPLICATION man DEc.2. 191s.

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FRANK A. LNDQUIST, OF NEW YORK, N. Y., ASSGNOR T0 WESTERN ELECTRIC GOM- rnnr, rivoonroaarnn, or new venir, n. Y., a

CORPORATION OF NEW YORK.

AUTOMATIC S'WITCHING MECI-IANISM.

Specification of Letters Patent.

Patented J an. 15, 1212u Application led December 2, 1916. Serial No. 134,573.

To all whom 'it may concern:

Be it known that I, FRANK A. LUivnQUis'r, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Automatic Switching Mechanisms, of which the following is a full, clear, concise, and exact deu scription.

This invention relates to automatic switches, and more particularly to automatic telephone exchange switches.

The object of this invention is to provide a switch in which one only of several idle trunks, that may be found simultaneously by a plurality of brushes, will be usexd, the remaining idle trunks found being left free to be selected by other switches. ln accordance with this object, several test brushes are provided for each set of line brushes. Said test brushes travel simultaneously over as many different groups of terminals, and upon contact with an idle trunk by oneor more of the test brushes, the progressive movement of all the test brushes is stopped and one only of the several idle trunks that may have been found will be selected and used by the set of line brushes.

Referring to the drawing, Figure 1 is a side elevation (partially in section) of a switch of the panel type employing this invention; Fig. 2 is a view showing in detail the arrangement of the controlling apparatus of the switch; and Fig. 3 is a sectional view on line 3-3 of Fig. 1.

Referring to the drawing, 1 represents a frame in which the rotatably and longitudinally movable shafts 2 and 10 are mounted. A ratchet wheel 3 is slidably mounted on the shaft 2 and is arranged to be engaged by a pawl 4, controlled by an electromagnet 5 to rotate said shaft. The shaft 2 is held in its normal rotary position by means of a pin 125 engaging a stop 124 fastened to the frame 1. An escapement rack comprising teeth 6 is carried by the shaft 2, and is arranged to coperate with an escapement pawl 7, controlled by an electromagnet 8, to permit said shaft 2 to be moved downward, step by step, by a spring 9. Arms 14 are spirally arranged about the shaft 2, and serve to Vcontrol the movement of the several brush carriages 12. rlhe movement of each carriage is controlled by a collar 13. There are ten of these brush carriages (only one being completelyshown as each one is of similar construction). rlhe brush carriage, to be opei'ated, depends on the positioning of the arms 14 on the shaft 2.

A spring 15, secured to the brush carriage 12, normally engages a catch 1G of the frame 1, and hold.' mal position. A rod 17 is mounted in the brush carriage 12, and is arranged to be moved longitudinally by the arm 14. A pin 1S on the rod 17 moves the spring 15 away from the catch 16 when the rod 17 is moved to the left, and allows the brush carriage to be moved downward with the shaft- 2. Brushes 19, 20, 21 and are attached to the carriage 12, and are arranged to engage the test terminals 23 of the terminal bank 24. The terminal. bank 24 is divided. into four groups, cach group having a brush associated therewith. Each sot of terminals 23 is associated with a trunk (not shown) leading to another switch. These trunks may be slipped in the various groups.

Arms 25 are arranged spirally around the shaft 10, and serve as stops for a brush carriage 2G, slidably mounted on another shaft 11 extending In the normal position of the switch an extension 36 of the brush carriage 26 engages a catch 27 of the rod 17, and prevents the brush carriage from moving downward. When the rod 17 is moved longitudinally by the arm 14, and after the shaft is rotated as hereinafter will more clearly appear, the' brush carriage 26 slides downwardly by its own weight in the following manner: As soon as the topmost arm 25 nieves out of engagement with extension 37, the brush carriage slides down the shaft 11 until stopped by the next arm 25, ete., until it reaches a position determined in a manner hereinafter described.

A sleeve 30 is mounted on the shaft 10, and is arranged to rotate with the shaft, but not to move longitudinally therewith. A cam 31 is secured to the sleeve 30, and is provided with a catch 35. Fig. 2 shows the arrangement of the apparatus around the cam 31, the apparatus being omitted from Fig. 1 to simplify the showing. A number the carriage in .its norparallel to the shafts 10 and 2.

7 ductor 50, finder brush 49, terminal 48, tele .tated.V The cam 31 is prevented normallyV from being rotated by a dog 32 controlled by a magnet 47.

It is believed that the invention will best jbe understood by describing the operation.l

' Vhen subscriber at substation A removes his receiver from the hook to make a call, his line 1s connected in any well-known manner, as by a line finder, to the switch shown i.

in the drawing. A circuit is thereupon closed for line relay 51 from grounded battery, left-hand winding of relay 51, conphone apparatus at substationA, terminal 54, finder brush 53, conductor 52, righthand winding of relay 51 to ground. Relay 51, at its armature and front contact, closes a circuit for slow-release magnet 56 from grounded battery, armature and frontcony tact of relay 51, conductor 55, slow-release magnet 56 to ground. Magnet 56 attracts its armature 57 against the action of spring 59. The attraction of the armature 57 allows holding pawl 58 to engage the teeth 3, and also moves rod 60 longitudinally, which allows the catches 61, 62 and 63 to engage levers 64, 65 and 66, respectively, so that when magnet 56 is denergized, spring 59 will return the rod 60 to its normal position, and the levers 64, 65 and 66 will move the slidably mounted clutch members 67, 68 and 69 to return the switch to its normal A position in a manner hereinafter described. VCatches 61 and 63 are pivotally mounted on the rod 60, but the catch 62 is pivotally mounted on a sleeve 101, which is slidably mounted on the rod 60. This sleeve 101 is, however, moved with the rod 60, at this time, by means of a pin 126, which is fastened to the rod.

Armature 57 also closes a break-point in the circuit for rotary magnet 5, so that when the calling subscriber dials and line relay 51 denergizes, the following circuit is closed at the armature and back vcontact of relay 51, each time the line circuit is opened, to cause the shaft 2 to be rotated the distance of one tooth of the ratchet wheel 3: Grounded battery, armature and back contact of relay 51, conductor 70, armature 57 and its front contact, conductor 71, magnet 5, conductors 72 and 73, normal rotary contact 74 to ground. Upon the rst energizaits left-hand armature and front contact, closes a substitute circuit to ground for the one above traced, for the rotary magnet, which is broken at thenormal contact-74nas soon as theshaft 2l `has rotated o nestep.

After the last impulse has been sent, relay 51 remains energized, thereby denergizing magnet 5, which, in turn, denergizes slow relay 7 5, which at its right-hand armature and back contact closes a circuit for the escape magnet 8 from grounded battery, springs 41 andA4 40, conductor39, magnet 8, conductorl 7 7, springs 126` and V121, conductor 38, right-hand armatureand backcontact of relay 75, conductor 78, rotary contact 74 in its off-normal position, to ground. I The rotary movement of shaft 2 positions the arms 14 so that one of them, corresponding tothe number of impulses sent, isin engagement with a rod 17, to allow the corp responding brush carriage 12 to movedownward y with the shaft 2 to hunt for idle trunks. Assuming that one impulse hasbeen sent, the topmost armf14 has moved the rod 17 longitudinally so that, as magnet 8 isen ergized and deenergized, the shaft 2 drops and the brush carriage 12 andthe shaft 10 are moved downward with the shaft 2. The brushes 19, 20, 21 and 22 on the brushcarriage 12 are thus moved over the test contacts of the bank 24. The circuit for operating magnet 8 includes springs 120 and 121, controlled by the armature 7 of said magnet, thus providing aself-interrupting circuit.

Assume that the brushes Y2O and A21 simuljtaneously 6nd idle trunks upon theuirst step downward of the shaftA 2, andthe other brushes. iind .busy trunks. In the circuit arrangement shown, a busy trunk has ground connected to its test terminal, and the test terminal ofan idle trunk is un- .grounded Therefore, the relays 42,' associated-'with Vbrushes V19 and'22, will be energized, the circuit foreach relay being from battery, conductor 80, relay 42, springs 44, 43, tothe corresponding brush, which'is connected to ground through the test ter minal of the busy lines. These relays 42 will become energized, and their armatures will allow the springs V,45 and 46 to separate. Since no ground is connected to the relays 42, associated with brushes 2O and 21, their contacts 45 and 46 remain closed, so that a circuit for magnet 47 is closed from grounded battery, conductor 80, springs 45 and 46 of the unoperated relays 42, conductor 81, off-normal Ysprings 831 and 84, which are closed as soon as the shaft moves down one step, conductor 82, magnet 47, springs 122 and 123, tovground. Magnet 47 attracts dog 32 out of the notch provided therefor in thefcam 31, thus allowing shaft 10 to be Arotated by spring 33. ,The dog separates the springs40V and 41, thereby opening the circuit of magnet 8 which stops further downward movement of the switch. The dog also separates the springs 122 and 123, which opens the circuit of magnet 47.

Since the lirst relay Ll2 is energized, its' armature moves its spring 43 out ofthe path of catch 35 of the cam 31. -When shaft 10 has rotated far enough, catch 35 engages spring 13 of the relay 42 associated with the brush 20. rllhis spring 43 is then separated from its associate spring 441, and is pushed into the slot 85 of the cam 31. The spring is so constructed as to stop further rotation of the shaft 10 when it reaches the bottom of the slot S5. The cam 31 is connected to ground, so that when it engages the spring 43, ground is connected to the test terminal of the trunk with which the brush 20 is connected, and any other multiples thereof, to cause them to test busy.

When the shaft 10 has rotated a certain amount, the uppermost arm 25 moves out of engagement with projection 37 of brush carriage 26 to allow the carriage to move down into engagement with the next arm 25, which will now be in a position to stop it on the idle trunk. The trunk seized is connected to conductors 86 and 87, which are multipled to brushes 110 and 111 (Fig. 3) of all the brush carriages 2G of the switch. The subscriber may now operate another switch in a similar manner, to complete the connection to the wanted subscriber.

lt will be noted that the terminal with which brush 21 is in engagement will still test idle, as no ground is connected thereto, so that it may be seized by another switch to which it is multipled.

As long as the line to substation A is in use, the line relay 51 will remain energized, as will also the slow relea-se magnet 56. As soon, however, as the line circuit is broken at substation A by the subscriber hanging up his receiver, relay 51 denergizes and magnet 56, after an interval, releases. The retraction of armature 57 withdraws holding pawl 58 from the rotary teeth 3, thereby permitting the shaft 2 to return to its normal rotary position under action of spring 95, where it is stopped by pin 125 on shaft 2 engaging pin 12a on frame 1.

The retraction of armature 57 also causes the catches 61 and G3 to move the levers G4 and 66 to the right, thus permitting the respective clutch members G7 and 69 on a constantly revolving shaft 93 to engage and rotate the drums 90 and 91, respectively. Catch 02 dees not move the lever 65 to the right at this time on account of the catch 100 being in engagement with the sleeve 101. Drum 90 winds up the tape 94 to which is attached the shaft 2, and also the lug 9G. As the shaft 2 reaches its normal vertical position, the lug 96 engages the catch G1 and moves the catch out of engagement with lever 64, which allows clutch member 07 to disengage drum 90. Shaft 2 is held in its normal vertical position by the escapement arm 7 engagingratchet 6.

Drum 91 winds up the tape 97 which is fastened to the shaft 11. Lug 99 is fastened to the shaft 11, so that, as the shaft is raised. it engages the displaced brush car riage 2G to return it to its normal position. Another lug 98 is fastened to the tape 97, and is so arranged that when the lug 99 has returned the carriage to its normal posit-ion, it engages the catch G3 to disengage the clutch member G9 from the drum 91. The shaft is then moved down by a spring 126, until a lug 127, fastened to the shaft, engages the frame 1.

The lug 98 also engages the catch 100, which releases the sleeve 101 mounted to slide on the rod 60, so that it is moved to the right by the action of spring 102. This sleeve 101 has pivoted thereto the catch 62, which moves the lever 05 to the right and throws the clutch member GS, carryii'ig the bevel gear 10-5 into engagement with the bevel gear 101V on the shaft 10, to rotate the shaft back to its normal position. lVhen the normal position is reached, the pin 105 engages the catch 02, and disengages it from the clutch G8.

The shaft 10 and brush carriage 12 are returned to their normal vertical position by spring 109, when the release magnet 5G is deenergized to withdraw pawl 58,which results in arm 11 being disengaged from rod 17.

lVhat is claimed is:

1. In a telephone system, in combination with groups of equivalent trunk lines, automatic switching means having line brushes and test brushes, fixed contacts for said lines in said switching means, a test contact for each line, testing means associated with said switching means including said test brushes for determining idle trunks in said groups, and means for connecting said line brushes with one of said idle trunks.

2. 1n a telephone system, in combination with groups of equivalent trunk lines, automatic switching means having line brushes and test brushes, fixed contacts for said lines in said switching means, a test contact for each line, testing means associated with said switching means including said test brushes, a member carrying said test brushes, a member supporting said line brushes, means for driving said test brush carrying member to cause said test brushes to test said groups simultaneously and to arrest the same when one or more idle trunks are reached, and means actuated thereby for driving said line brush supporting member to cause line brushes to engage one of said selected idle trunks.

3. In an automatic switch,a set of brushes, a plurality of sets of terminals arranged for engagement by said set ofbrushes, means `for testing simultaneously a plurality of said terminals, means operated when one or more sets of terminals are found idle for determining which of said termiiiials Will be engaged by said set of brushes, and means .tor causing said brushes to engage said predetermined set of terminals.

4f. In an automatic switch, a set of brushes, groups of sets of terminals arranged for engagement by said set of brushes, a plurality ot'v test brushes associated with said set oi brushes one 'for each group, said test brushes being arranged simultaneouslyT to test terminals in diderent groups, mea-ns for moving said test brushes, means operated when one or more idle terminals are found for determining which of the idle terminals Will be engaged by said set-'oi brushes, and means for causing said brushes to engage said predetermined set ot terminals.

5. In an automatic switch, a set of brushes, groups of sets of terminals arranged for engagement by said set ot brushes, a plurality of test brushes associated with said set of brushes one for each group, said test brushes being arranged simultaneously to test terminals in each group, means for movling said test brushes, a relay associated with each of said test brushes, means controlled by said relays for selecting the group conn taining the set of terminals to be engaged controlled by said relays for controlling the connection between said brushes and said sets of terminals.

7. In an automatic switch, a plurality of sets of brushes, groups of terminal sets arranged for engagement by said brushes respectively, brush selecting means for rendering one of said sets of brushes operative, means for simultaneously testing a plurality of terminal sets in the group associated with said selected sets of brushes, means for determining which of said terminal sets will be engaged by said selected set of brushes when one or more terminal sets are found idle, and means for causing said set of brushes to engage said predetermined set of terminals.

In Witness whereof, hereunto subscribe my name this 29th day of November A. D.,

FRANK A. LUNDQUIST.

, Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

